Attempts to place limits on the conduct of conflict raise many practical and political concerns. This article asks how debates regarding precautionary approaches to risk might inform discussions about how limits are set for armed conflict. The 2008 Convention on Cluster Munitions (CCM) provides the starting point for this analysis. While the adoption of this convention represents a major achievement in multilateral humanitarian disarmament, its provisions are open to question about their meaning. As argued, the manner in which the CCM was agreed provides an opening for embedding precautionary thinking into its future interpretation. Experiences with precautionary approaches to risk are surveyed with a view to considering what lessons they hold for the central prohibition of cluster munitions in the CCM, its novel provisions for Victim Assistance, and its possible implications for the use of explosive force. The overall goal is to ask how debates about the precautionary principle might enhance the protection of civilian populations.